Physics 1112 COOPerative #1F Relative Motion F24 v2 Problems #1F: Reference
Frames
PHYS 1112: COOP
* Work on this problem in groups of 3 (or 4) as designated by your instructor.
* Be sure to read and follow the instructions carefully.
* Share and discuss ideas with the rest of your group, try to come to a consensus,
and be sure that everyone in the group remains up to speed.
* Please ask an instructor to check your work at specified checkpoints or if you
have questions that your group is unable to resolve on its own.
YOUR NAME:
NAMES OF THE REST OF YOUR GROUP:
#1. [Rolling Wheel] A wheel of radius R
rolls without slipping at constant speed v
on flat, horizontal ground, as shown. Our
goals are to compare motions of various
points (A, B, C, D) on the wheel as seen
from two different reference frames–the
ground (G) and the center of the wheel
(W)–and to relate velocities and
accelerations
(magnitudes and directions) of those
points as seen in each reference frame.
You should use a wheel or other object that can roll to demonstrate the
observations and findings you explore in this activity.
Physics 1112 DISC COOP #1F - 1 Cornell University
, [Activity CONTINUES on the next page.]
(a) Make a quick prediction: What do you think is the direction of the velocity of point C
on the wheel relative to the ground (𝐯"⃑C/G)? Share your prediction with your group.
Circle your prediction here:
(A) ↑ (B) ↗ (C) → (D) ↘ (E) Other
Now we'll check our prediction by examining and relating motions in two different
reference frames: the center of the wheel (W) and the ground (G).
(b) As seen in the wheel's reference frame (a reference frame attached to the
center of the wheel), what is the velocity of the ground relative to the center of the
wheel (𝐯"⃑G/W)? Write your answer as a direction arrow + speed in terms of speed v.
(c) Is any point on the wheel momentarily moving
with same velocity as the ground relative to the center
of the wheel? If so, which point? Why?
Demonstrate this finding using your wheel.
(d) What is the speed (in terms of v) of each labeled point on the wheel (A, B, C,
D) relative to the center of the wheel?
vA/W = vB/W = vC/W = vD/W =
Show the velocities of these points as arrows drawn
to scale on the diagram above and marked with
magnitudes in terms of speed v.
Physics 1112 DISC COOP #1F - 2 Cornell University
Frames
PHYS 1112: COOP
* Work on this problem in groups of 3 (or 4) as designated by your instructor.
* Be sure to read and follow the instructions carefully.
* Share and discuss ideas with the rest of your group, try to come to a consensus,
and be sure that everyone in the group remains up to speed.
* Please ask an instructor to check your work at specified checkpoints or if you
have questions that your group is unable to resolve on its own.
YOUR NAME:
NAMES OF THE REST OF YOUR GROUP:
#1. [Rolling Wheel] A wheel of radius R
rolls without slipping at constant speed v
on flat, horizontal ground, as shown. Our
goals are to compare motions of various
points (A, B, C, D) on the wheel as seen
from two different reference frames–the
ground (G) and the center of the wheel
(W)–and to relate velocities and
accelerations
(magnitudes and directions) of those
points as seen in each reference frame.
You should use a wheel or other object that can roll to demonstrate the
observations and findings you explore in this activity.
Physics 1112 DISC COOP #1F - 1 Cornell University
, [Activity CONTINUES on the next page.]
(a) Make a quick prediction: What do you think is the direction of the velocity of point C
on the wheel relative to the ground (𝐯"⃑C/G)? Share your prediction with your group.
Circle your prediction here:
(A) ↑ (B) ↗ (C) → (D) ↘ (E) Other
Now we'll check our prediction by examining and relating motions in two different
reference frames: the center of the wheel (W) and the ground (G).
(b) As seen in the wheel's reference frame (a reference frame attached to the
center of the wheel), what is the velocity of the ground relative to the center of the
wheel (𝐯"⃑G/W)? Write your answer as a direction arrow + speed in terms of speed v.
(c) Is any point on the wheel momentarily moving
with same velocity as the ground relative to the center
of the wheel? If so, which point? Why?
Demonstrate this finding using your wheel.
(d) What is the speed (in terms of v) of each labeled point on the wheel (A, B, C,
D) relative to the center of the wheel?
vA/W = vB/W = vC/W = vD/W =
Show the velocities of these points as arrows drawn
to scale on the diagram above and marked with
magnitudes in terms of speed v.
Physics 1112 DISC COOP #1F - 2 Cornell University
